Qhov txawv ntawm Klenow thiab T4 DNA polymerase yog tias Klenow fragment yog ib feem loj ntawm E. coli DNA polymerase 1 thaum T4 DNA polymerase yog DNA polymerase 1 ntawm bacteriophage T4.
DNA polymerases yog cov enzymes uas catalyze tsim DNA los ntawm kev ntxiv deoxyribonucleotides rau 3′-OH kawg ntawm ib tug pre-existing primer. Muaj ntau hom DNA polymerases. Feem ntau DNA polymerases siv nyob rau hauv molecular biology yog prokaryotic DNA polymerases. Klenow fragment thiab T4 DNA polymerase yog ob hom DNA polymerases uas muaj keeb kwm prokaryotic. Klenow fragment yog ib feem loj uas yog tsim los ntawm cleavage ntawm E.coli DNA polymerase 1 rau hauv ob feem ntawm cov kab mob protease subtilisin. T4 DNA polymerase yog DNA polymerase 1 ntawm bacteriophage T4. Klenow thiab T4 DNA polymerase muaj 5′ → 3′ polymerase thiab 3′ → 5′ exonuclease kev ua. Lawv ob leeg tsis muaj 5′ → 3′ exonuclease kev ua, ua rau lawv tsim nyog rau ntau daim ntawv thov nyob rau hauv molecular biology.
Klenow yog dab tsi?
Klenow fragment yog DNA polymerase uas muaj txiaj ntsig zoo hauv molecular biology. Thaum E. coli DNA polymerase 1 raug kev zom zaub mov proteolytic los ntawm cov kab mob protease, subtilisin, nws ua rau ob ntu: ib qho yog ib qho loj, thiab lwm qhov yog ib qho me me. Klenow fragment yog cov tawg loj uas yog 68 kDa loj. Klenow fragment muaj 5′ → 3′ polymerase thiab 3′→ 5′ exonuclease (proofreading) kev ua ub no ntawm DNA Pol I. Qhov 3′→ 5′ exonuclease kev ua ntawm Klenow fragment pab txhawb kev tshem tawm ntawm incorrectly ntxiv bases li polymerization zuj zus. Klenow fragment tsis muaj 5′ → 3′ exonuclease kev ua, uas yog qhia los ntawm tag nrho-ntev los yog zoo E.coli DNA polymerase 1. Nws yog qhov zoo thaum tsuas yog xav tau kev ua haujlwm polymerization nkaus xwb. Klenow fragments yog siv los sau 5' overhangs, synthesis of probes, sequencing DNA, synthesis of two-stranded DNA, synthesis of cDNA second strand and site-directed mutagenesis.
Daim duab 01: Klenow Fragment
Hauv qee daim ntawv thov, 3′→ 5′ exonuclease kev ua ntawm Klenow fragment kuj dhau los ua qhov tsis xav tau. Nws tuaj yeem raug tshem tawm los ntawm kev qhia txog kev hloov pauv mus rau cov noob uas cov lej rau Klenow fragment. Qhov tshwm sim Klenow fragment yog hu ua exo-Klenow fragment. Yog li ntawd, exo-Klenow fragment tsuas muaj 5′ → 3′ polymerase kev ua ntawm E. coli polymerase 1.
T4 DNA Polymerase yog dab tsi?
T4 DNA polymerase yog DNA polymerase uas catalyzes synthesis ntawm DNA. Nws yog ib qho protein coded los ntawm Bacteriophage T4. Structureally, T4 DNA polymerase yog ib qho 898 amino acid residue protein (molecular hnyav ntawm 103.6 kDa). Nws yuav tsum tau ib tug template thiab ib tug primer rau catalyze lub synthesis.
Daim duab 02: T4 DNA Polymerase
Zoo ib yam li Klenow fragment, T4 DNA polymerase muaj ob qho tib si 5′ → 3′ polymerase thiab 3′ → 5′ exonuclease cov dej num. Ntxiv mus, nws tsis muaj 5′ → 3′ exonuclease kev ua thiab. T4 DNA polymerase yog qhov tseem ceeb hauv kev sau ntawm 5'-protruding kawg ntawm DNA tawg. Nws kuj yog feem ntau siv rau 5'-kawg lossis 3'-kawg-labeling ntawm ob-stranded DNA. T4 DNA polymerase feem ntau siv rau hauv kev ua tsis ncaj ncees lawm. Qhov 3′→5′ exonuclease (proofreading) kev ua ntawm T4 DNA polymerase muaj zog (ntau tshaj 200 zaug) dua cov Klenow fragment. Qhov tseem ceeb tshaj plaws, T4 DNA polymerase muaj cov txheej txheem siab (400 nucleotides ib ob).
Dab tsi yog qhov zoo sib xws ntawm Klenow thiab T4 DNA Polymerase?
- Klenow thiab T4 DNA polymerase yog ob lub prokaryotic polymerases.
- Ob lub polymerases muaj 5′ → 3′ polymerase thiab 3′→ 5′ exonuclease kev ua haujlwm.
- Lawv tsis nthuav tawm 5′→3′ kev ua haujlwm exonuclease.
- Ob lub enzymes xav tau ib lub qauv thiab cov primer los ua kom cov synthesis ntawm DNA.
- Cov enzymes no tuaj yeem ua kom sov tsis muaj zog ntawm 75 0
Qhov txawv ntawm Klenow thiab T4 DNA Polymerase yog dab tsi?
Qhov sib txawv tseem ceeb ntawm Klenow thiab T4 DNA polymerase yog lub hauv paus ntawm txhua enzyme. Klenow fragment yog los ntawm ib tug kab mob thaum T4 DNA polymerase yog los ntawm ib tug bacteriophage uas yog ib tug kab mob. T4 DNA polymerase muaj cov txheej txheem siab dua li Klenow fragment. Ntxiv mus, T4 DNA polymerase muaj cov ntaub ntawv pov thawj muaj zog dua li Klenow fragment. Yog li, qhov no yog lwm qhov sib txawv ntawm Klenow thiab T4 DNA polymerase.
Cov ntaub ntawv hauv qab no-daim duab qhia ntau qhov sib txawv ntawm Klenow thiab T4 DNA polymerase hauv daim ntawv teev npe.
Summary – Klenow vs T4 DNA Polymerase
Klenow fragment yog ib feem loj ntawm E. coli DNA polymerase 1. Nws tsuas muaj 5′→3′ polymerase thiab 3′→5′ exonuclease cov dej num. Nws tsis muaj 5′ → 3′ exonuclease kev ua ntawm cov E. coli DNA pol 1. Yog li ntawd, Klenow fragment yog ib tug kab mob polymerase. Ntawm qhov tod tes, T4 DNA polymerase yog polymerase coded los ntawm bacteriophage T4. Zoo ib yam li Klenow fragment, nws muaj 5′ → 3′ polymerase thiab 3′ → 5′ exonuclease kev ua ub no, thiab nws tsis muaj 5′ → 3′ exonuclease kev ua. Txawm li cas los xij, T4 DNA polymerase muaj cov txheej txheem siab thiab kev ua pov thawj siab dua li Klenow fragment. Yog li, qhov no yog qhov sib txawv tseem ceeb ntawm Klenow thiab T4 DNA polymerase.
